Conventional construction practices frequently call for the provision of a space between adjacent structures or substructures, for example to accommodate normal expansion and contraction, to afford a degree of relative motion to limit damage from seismic activity, or other reasons. Such spaces are covered by architectural joint systems, designed to permit the necessary motion of the adjacent structures. In one well known design of such architectural joint systems, a flat cover plate is provided to span the space between the adjacent, relatively movable structures, typically with special support elements being mounted at each side to provide for support and control of the cover plate. The cover plate has a width sufficient to accommodate the maximum anticipated separation of the adjacent structures, and the arrangement also allows for the structures to approach each other to a calculated minimum separation by sliding underneath the cover plate.
In some architectural joint systems of the general type described above, it is common to provide means for maintaining the cover plate in a centered or approximately centered relationship to the adjacent structures, as the space between them expands and contracts. One advantageous arrangement for this purpose involves the provision of guide rail members secured to the respective structures, at opposite sides of the intervening space. A plurality of centering bars, of substantially greater length than the maximum space between the structures, are provided with guide means at their opposite ends received in grooves in the respective guide rail members. The centering bars are pivotally connected at their midpoints to center points of the cover plate. Accordingly, as the adjacent structures move toward and away from each other, the centering bars rotate, maintaining their center points midway between the adjacent structures and at the same time serving to maintain the location of the cover plate evenly centered regardless of the width of the space. Prior art examples of such mechanisms are represented by the Schmitt U.S. Pat. No. 3,183,626 and the Dunsworth U.S. Pat. No. 4,566,242, for example. The present invention is directed to a multi-functional, universal guide rail member which, in addition to other uses, is advantageously employed in a cover mechanism of this general type, leading to substantial economies of manufacture and installation.
In accordance with one aspect of the invention, a unique and advantageous universal, multi-functional guide rail element is provided, which can be utilized in a wide variety of structural environments, resulting in an enormous reduction in the inventory requirements of specialized parts. In this respect, in a common form of installation of the cover structures for architectural joint systems, it is customary to provide recesses or block-outs in the adjacent concrete structures, for receiving the components of the joint system while providing a substantially flush surface configuration. Typically, the dimensions of such block-out areas may vary widely, not only by initial design but as a function of tolerance variations in the construction procedure. Accordingly, it has been necessary, heretofore, for the joint manufacturer to carry in its regular operating inventory a wide variety of sizes and shapes of specially contoured parts, for installation in a wide variety of configurations. With the system of the present invention, however, a single, multi-functional guide rail member may be combined with a wide variety of standard off-the-shelf components, such as channels and angles, to enable installations in a wide variety of configurations. Thus, for a given strength and weight of structure, a single multi-functional guide rail member may be employed for all installed configurations. For different depths and widths of block-out areas, the multi-functional guide rail member is employed with stock, off-the-shelf channel and/or angle members of different standard sizes and configurations. Where predicted tolerances are not realized, and special sizing is required, that can be performed with inexpensive modifications to the off-the-shelf components without requiring new designs or modifications to the structure and configuration of the guide rail member itself.
As a specific: feature of the invention, a novel and improved guide rail member of multi-functional configuration is provided, which incorporates in a single, continuous (typically extruded) section, a guide groove for engaging and slidably retaining the end of a centering bar, an upwardly facing continuous screw-receiving slot, provided on its sidewalls with thread-engaging serrations, and a continuous, open-sided bolt-receiving slot, for engagement of anchoring bolts. By combining all of these features into a unitary, multi-functional guide rail structure, the required number of specially configured components is reduced to a minimum, and the variables involved in a given installation, be they by design or tolerance variation, are accommodated by the installation of off-the-shelf components, such as channels, angles and the like.
The multi-functional guide rail member of the invention has significant utility also in architectural joint systems in which a centering means is not employed, for example in the mounting of a cover plate in fixed relation to one of two movable structures, allowing the plate to move relative to the other structure to accommodate expansion and contraction, without regard to attempting to center the cover plate. In these and other modes of utilization, some but less than all of the functional features of the member may be employed. Nevertheless, significant advantages are realized in that a single, versatile component can be inventoried to perform a multiplicity of tasks in the various possible structural configurations.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments of the invention and the accompanying drawings.